P B Sunil Kumar

Blebs are membrane protrusions that appear during several physiological processes in eukaryotic cells. The phase behavior and kinetics of blebbing in cellular membrane is investigated computationally using a particle-based model for self-assembled lipid vesicles apposed to an elastic meshwork, mimicking a cell's cytoskeleton. We found that blebbing is induced when the cytoskeleton is subjected to a localized ablation, detachment from the membrane, or a uniform contraction. These results are in good agreement with experiments.

We propose a hydrodynamic model for pattern formation in mixtures of molecular motors and microtubules. Our model invokes a vector field describing the local microtubule orientation, and two scalar density fields associated to molecular motors which either attach to and move along the microtubule, or diffuse within the solvent. We present results for pattern formation in the background of two preformed aster-like configurations, placed symmetrically in the simulation box, in an attempt to mimic some features of patterns obtained In vivo.

Self-assembled multicomponent lipid vesicles are studied via large scale dissipative particle dynamics simulations. We investigated the effect of volume fraction, line tension, surface tension, and transbilayer asymmetry in the lipid distribution on the dynamics and morphology of the membrane. We found that in the of symmetric transbilayer lipid distribution, the dynamics is rich characterized by coalescence of flat patches, budding and coalescence of caps. However, an asymmetric transbilayer lipid distribution sets a spontaneous curvature and lead to dramatically slow dynamics at intermediate values of the surface tension.